Abstract:

Effect of arbuscular mycorrhizal fungi on drought resistance of clover. Tolerance of
mycorrhized clover (Trifolium alexandrinum L.) to drought depends on the arbuscular
mycorrhizal fungi associated to the host plant. Five arbuscular mycorrhizal fungi
isolates were collected from five Moroccan date palm grove's soils and were investigated for
their ability to improve the plant tolerance to water deficit stress. Applying a
constraint of 30% field capacity reduces severely the mycorrhizal rate in the root cortex of
most of the tested isolates. Fungi collected from Aoufous date palm grove were less
affected by the drought than the other strains, such as Glomus
and Sclerocystis
isolated from Agdz soil. The effect of mycorrhization on the biomass production occurred for
the isolate of Aoufous and Glomus mosseae (reference strain obtained from INRA Dijon,
France). These fungi allowed the plants to maintain its water content, water potential and
its leave transpiration at high levels compared to the non inoculated plants. The values of
stomata resistance and the saturation deficit in water remained lower for mycorrhized
plants than non-mycorrhized. Ones further more, the isolate of Aoufous and Glomus
mosseae were the most virulent colonizing the host plants regard less of the level of water
deficit in the soil. Autochthon isolates originating Aoufous date palm grove was as
efficient
as Glomus mosseae.